1. Field
The invention has to do with tensioned flexible heads of drums of all kinds as musical instruments.
2. State of the Art
Drums as musical instruments are normally made with flexible heads of various sheet materials, usually a plastic such as a Mylar, arranged to be tensioned after installation on the hollow body of the drum. As customarily produced, such drumheads may be single sheets, or they may be double sheets with a liquid therebetween.
It has been the practice with some drummers to cut a circular aperture in the flexible diaphragm sheet of a single sheet drumhead for the purpose of releasing air lock and sonic charge within the hollow interior of the drum to augment and beneficially modify sound characteristics, but this has had a tendency to distort vibration of such sheet and to result in relative short life for the drumhead by reason of splitting and cracking of the sheet marginally of the aperture.